A diversity manager for South Wales Police who claims he was racially abused made a junior colleague “shake with fear”, a tribunal has heard.

Samuel Johnson, 49, the force’s head of internal diversity until 2005, claims he was called a “baboon” and a “criminal” in the police unit where he says racist language was commonplace.

He is claiming racial discrimination against the force after allegedly being subjected to unfair surveillance, including having his diary copied.

But yesterday the tribunal heard Mr Johnson himself was unprofessional and would swear, be abusive and shout at colleagues.

South Wales Police allege Mr Johnson would miss meetings and had been given the nickname “the late Sam Johnson”.

Diversity worker Suzanne Sweeney said her relationship with Mr Johnson, then her boss, became “worse than she could possibly ever imagine”.

She told the tribunal: “You raised your voice, you were nasty, you were sharp. I was frightened of you. When things were at their worst I was visibly shaking at the thought of having meetings with you.”

Ms Sweeney said when she tried to leave a meeting “for fear of her emotional health” Mr Johnson screamed at her “don’t you dare leave”.

She also alleges that on at least two occasions Mr Johnson locked the door after calling her in for meetings.

Mr Johnson denies all the allegations.

Representing himself, he asked Ms Sweeney: “If I had been shouting at you, raising my voice, do you think other people in the office would have heard?

“Lots of other witnesses have come forward and said they never heard me swear and never heard me shout. They also say I never locked any doors.”

He also denies being unprofessional and said the missed meetings referred to were while he was on annual leave.